Friday, December 21, 2018
CapitalPress.com
7
Researcher identifies new weapons against slugs
Essential oils,
nematodes prove
effective against
common pest
By MATEUSZ PERKOWSKI
Capital Press
Essential oils from thyme
and spearmint are prov-
ing lethal to crop-damag-
ing slugs without the tox-
icity to humans, animals
or the environment that
chemical solutions can
present.
An added advantage of
these oils is the rapid mor-
tality they cause in slugs,
whereas one of the most
common chemical mol-
luscicides used by Oregon
farmers, iron phosphate,
simply causes them to stop
feeding, said Rory McDon-
nell, Oregon State Universi-
ty’s slug specialist.
“The oils were essen-
tially just as effective as
metaldehyde,” another com-
Courtesy of Robin Rosetta/OSU
New weapons are being discovered in the battle against slugs.
mon molluscicide, McDon-
nell said during the Oregon
Seed League’s annual meet-
ing, held in Salem, Ore., on
Dec. 10-11.
Thyme and spearmint
oils achieved 100 percent
mortality at a concentration
of just 0.25 percent, most
likely through direct con-
tact with slugs — though
it’s possible their volatile
emissions could also serve
as repellents for the pest,
McDonnell said.
Because they’re natu-
ral compounds, these oils
would be exempt from the
U.S. Environmental Protec-
tion Agency’s registration
and residue tolerance reg-
ulations for conventional
pesticides, he said.
Before they could be
commercialized as bio-
logical pesticides, data
would need to be submit-
ted to the Oregon Depart-
ment of Agriculture proving
they’re not toxic to humans
or non-target organisms,
though this should not be
a big obstacle, McDonnell
said.
“I’ll eat my hat if it’s
toxic,” he said.
McDonnell was hired
by OSU in 2016 after Ore-
gon farmers told the uni-
versity’s leaders that more
research was needed to fight
slugs, which have become
increasingly destructive in
recent years.
Another positive devel-
opment from McDonnell’s
research is the discovery
of a nematode that’s natu-
rally parasitic to grey field
slugs — phasmarhabdi-
tis hermaphrodita — on
OSU’s campus in Corvallis,
Ore.
The location if the dis-
covery was ironic given that
McDonnell had traveled
thousands of miles around
the state searching for the
species, which is native to
Europe and used in slug
control there.
“The darn thing was
a stone’s throw from my
office,” he said.
Since then, McDonnell
has discovered two other
nematode species in Oregon
that show promise as biolog-
ical control agents.
In the United Kingdom,
the phasmarhabditis her-
maphrodita nematode is
sold as a commercial biope-
sticide that’s been shown to
reduce slug damage in win-
ter wheat by 85 percent, he
said.
The nematode finds a
hole in the back of a slug’s
head, then vomits up a bac-
terial soup that’s toxic to
the gastropod. As the slug’s
body decomposes, the nem-
atode’s offspring feed on its
corpse.
The BASF chemical
company also markets the
nematode in Europe, pro-
ducing it in enormous vats
through a secret process,
McDonnell said.
Before the nematode can
be commercialized in the
U.S., BASF or another pes-
ticide manufacturer would
need to demonstrate to
USDA that it’s not harmful
to other species, such as the
native banana slug.
“I think that would be a
major stumbling block,” he
said.
Trade worries loom over pulse acreage
Uncertainty over
foreign trade leaves
growers up in the air
By MATTHEW WEAVER
Capital Press
Capital Press File
Dry beans are sorted at the Treasure Valley Seed Co.
production facility in Homedale, Idaho. Growers are worried
about continuing trade concerns as they make plans for next
year.
decline unless trade disputes
change.
The U.S. has about 2.2
million acres devoted to
pulse crops, with roughly
inquiries, McGreevy said.
“Maybe we’re in early
days, but any discussion
towards trying to resolve
these trade disputes and tar-
iffs are positive,” he said.
“These tariffs are certainly
having an impact, but we
do not expect them to last
forever.”
Domestic sales continue
to grow, McGreevy said.
“So it’s not all dark-
ness,” he said. “We believe
very strongly that long-
term these crops are going
to have increased consump-
tion here in the U.S. market
as well as overseas.”
Populations continue to
grow and pulses are the least
expensive proteins available
for purchase, McGreevy
said. He also pointed to new
products and the movement
towards more plant-based
foods.
“In periods of uncertainty,
which we are in, I think it’s
best to stay the course and
make sure the cropping
systems you have in place
— which include pulses
in the rotation — are part
of your bread basket,” he
said.
800,000 acres of peas;
800,000 acres of lentils and
600,000 to 700,000 acres
of chickpeas, McGreevy
said.
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Pulse growers will have
to consider low prices and
trade barriers as they decide
how many acres to plant this
spring, the leader of the USA
Dry Pea and Lentil Council
says.
“It would be wonderful
to be optimistic and think all
the trade disputes are going
to be resolved by the time
spring planting comes, but
that may be a little too opti-
mistic,” said Tim McGreevy,
council CEO.
McGreevy
said
he
expects pulse acres to
If growers keep a pulse
in their crop rotation,
they’ll decide which pulse
crop to raise, McGreevy
said.
Trade tariffs in China and
India remain in place, even
though there’s been move-
ment with the North Amer-
ican Free Trade Agree-
ment and a recent meeting
between President Don-
ald Trump and China Presi-
dent Xi Jinping, McGreevy
said.
In spite of the posi-
tive discussions, the indus-
try hasn’t seen any sales or
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